Radial Compressor

ABSTRACT

A radial compressor includes a rotor, a housing, and a radial compressor impeller which is rotationally fixed to the rotor. The radial compressor impeller has a wheel disk on which rotor blades are arranged in the circumferential direction, the rotor blades have a leading edge and a trailing edge. The radial compressor includes an impeller hub in the region in front of the leading edge of the rotor blades of the radial compressor impeller, the hub is arranged on the end of the rotor and/or the wheel disk in a concentric and rotationally fixed manner. Rotor blades with leading edges and trailing edges are also arranged on the impeller hub in the circumferential direction.

PRIORITY CLAIM

This is a U.S. national stage of application No. PCT/EP2017/056336, filed on Mar. 17, 2017. Priority is claimed on the following applications: Country: Germany, Application No.: 10 2016 108 762.9, filed: May 12, 2016, the content of which is/are incorporated herein in its entirety by reference

FIELD OF THE INVENTION

The present invention relates to a radial compressor comprising a radial compressor impeller, a wheel disc with moving blades arranged evenly distributed in the circumferential direction having a leading edge as well as an trailing edge, the radial compressor impeller being attached to a rotor, on which an impeller hub adjoining the radial compressor impeller is attached.

BACKGROUND OF THE INVENTION

Radial compressors convert mechanical energy into pressure energy in that they utilize the centrifugal acceleration, they substantially consists of an impeller, which is attached to a driving rotor, a diffuser and a housing. The impeller comprises a plurality of moving blades and as a function of the purpose of operation, the mechanical embodiment of the impeller is carried out in the manner of a closed or of an opened impeller. In the case of closed impellers, the moving blades are provided with a shroud, in the case of open impellers, the blades have a clear outside edge.

The conveying gas is axially sucked in approximately in the centre of the compressor and compressed by the centrifugal force and accelerated towards the outside, wherein in the diffuser arranged on the circumference side the kinetic energy is converted for the greatest part into additional pressure and the conveying gas further compressed.

The energy conversion in radial compressors involves corresponding flow, friction and gap losses, which is why it is important for increasing the efficiencies to not only optimise the radial compressor impeller alone, but also consider the adjoining components.

In DE 691 06 179 T2 a diagonal compressor is described and shown, the same comprises an impeller with moving blades and a moving hub following thereon on the end of the rotor.

An impeller hub lies in the inlet region of a radial compressor and depending on the size of the impeller hub, the maximum inlet area of the medium to be compressed and thus of the suction volume flow from the leading edge limited.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a radial compressor impeller which makes possible an enlarged inlet area at the start of the compression from the leading edge.

According to the present invention, this object is achieved by a radial compressor comprising a rotor that is rotatably mounted in a housing, on which a radial compressor impeller is arranged in a rotationally fixed manner. The radial compressor impeller comprises a wheel disc, on which moving blades are arranged in the circumferential direction and which have a leading edge and an trailing edge.

In the region in front of the leading edge, the radial compressor impeller comprises an impeller hub which at an end of the rotor is arranged on the same in a concentric and rotationally fixed manner.

On the impeller hub, moving blades are innovatively arranged in the circumferential direction, thus the impeller hub now constitutes a part of a bladed flow passage and the maximum inlet area in the suction mouth of the radial compressor impeller increases because of this in favour of a higher suction volume flow.

The distribution of the moving blades of the wheel disc and of the moving blades of the impeller hub can coincide and thus form a continuous blade profile, a not-continuous blade profile with non-corresponding distribution of the moving blades is alternatively also possible.

It is also conceivable that the number of the moving blades of wheel disc and impeller hub differs.

It is additionally also conceivable that between the moving blades of the impeller hub and/or of the wheel disc, guide blades are arranged.

In principle, the impeller can be open or closed, an impeller hub that is closed or partly closed towards the circumferential direction is likewise conceivable.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is further described in detail taken in conjunction with the drawings in which:

FIG. 1: shows an extract of a cross section through the arrangement in a radial compressor according to the invention with open impeller hub, in particular in the region of the wheel disc and of the impeller hub; and

FIG. 2: shows an extract of a cross section through the arrangement in a radial compressor according to the invention with closed wheel disc or closed impeller hub, in particular in the region of the wheel disc and of the impeller hub.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

In FIG. 1, the radial compressor according to the invention is shown in cross section in the form of an extract.

In a preferred embodiment, the radial compressor comprises a rotor 10, a housing which is not shown and a radial compressor impeller 11, which is arranged on the rotor 10 in a rotationally fixed manner.

The radial compressor impeller 11 comprises a wheel disc 12, on which in the circumferential direction moving blades 13 are arranged, which comprise a leading edge 14 and an trailing edge 15.

In the region in front of the leading edge 14 of the moving blades 13 of the radial compressor impeller 11, the radial compressor comprises an impeller hub 16, which is arranged at the end of the rotor 10 and/or on the impeller 12 in a rotationally fixed manner on the same.

On the impeller hub 16, moving blades 17 are arranged in the circumferential direction which in turn comprise leading edges 18 and trailing edges 19.

In an alternative embodiment the circumferential-side distribution of the moving blades 13 of the wheel disc 12 and of the moving blades 17 of the impeller hub 16 of the radial compressor according to the invention can coincide, so that substantially a continuous blade profile is formed.

In a further alternative, the circumferential-side distribution of the moving blades 13 of the wheel disc 12 and of the moving blades 17 of the impeller hub 16 of the radial compressor according to the invention can be distinct, so that no continuous blade profile is formed.

Optionally it is also conceivable that the number of the moving blades 17 of the impeller hub 16 is distinct from the number of the moving blades 13 of the wheel disc 12.

A further embodiment of the radial compressor according to the invention is obtained in that between the moving blades 13, 17 of the impeller hub 16 and/or of the wheel disc 12, guide blades which are not shown are arranged.

Further alternatives still materialise with regard to the configuration of the wheel disc 12, which on the one hand can be configured open or, on the other hand, the moving blades 13 can be provided with a shroud 21 (FIG. 2). Likewise, the impeller hub 16 can be designed open on the one hand or the moving blades 17 be provided with a shroud 20 on the other hand. (FIG. 2)

Thus, while there have shown and described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto. 

1-9. (canceled)
 10. A radial compressor comprising: a rotor, a housing and a radial compressor impeller, arranged on the rotor in a rotationally fixed manner; the radial compressor impeller comprising a wheel disc, and a first plurality of moving blades arranged on the radial compressor impeller, the first plurality of moving blades in a circumferential direction comprising a leading edge and an trailing edge; the radial compressor further comprising an impeller hub in the region in front of the leading edge of the first plurality of moving blades, the impeller hub arranged at an end of the rotor and/or on the wheel disc in a concentric and rotationally fixed manner; and a second plurality of moving blades having leading edges and trailing edges arranged on the impeller hub in the circumferential direction.
 11. The radial compressor according to claim 10, wherein a circumferential-side distribution of the first plurality of moving blades of the wheel disc and of the second plurality of moving blades of the impeller hub coincides thus forming a substantially continuous blade profile.
 12. The radial compressor according to claim 10, wherein a circumferential-side distribution of the first plurality of moving blades of the wheel disc and of the second plurality of moving blades of the impeller hub is distinct thus not forming a continuous blade profile.
 13. The radial compressor according to claim 10, wherein the number of the second plurality of moving blades of the impeller hub is distinct from the number of the first plurality of moving blades of the wheel disc.
 14. The radial compressor according to claim 12, additionally comprising guide blades arranged between the first plurality of moving blades of the impeller hub and/or the second plurality of moving blades of the wheel disc.
 15. The radial compressor according to claim 10, wherein the wheel disc is open.
 16. The radial compressor according to claim 10, wherein the wheel disc is closed by a shroud.
 17. The radial compressor according to claim 10, wherein the impeller hub is open.
 18. The radial compressor according to claim 10, wherein the impeller hub is closed by a shroud.
 19. The radial compressor according to claim 11, wherein a circumferential-side distribution of the first plurality of moving blades of the wheel disc and of the second plurality of moving blades of the impeller hub is distinct thus not forming a continuous blade profile.
 20. The radial compressor according to claim 11, wherein the number of the second plurality of moving blades of the impeller hub is distinct from the number of the first plurality of moving blades of the wheel disc.
 21. The radial compressor according to claim 12, wherein the number of the second plurality of moving blades of the impeller hub is distinct from the number of the first plurality of moving blades of the wheel disc. 